反应详情

温度

150 °C

Under argon 19.4 g (100 mmol) of 5-chloro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carbaldehyde (II-1) were initially charged in dimethylformamide. This was followed by the addition of 8.6 g (150 mmol) of potassium fluoride (KF water content 0.05%), heating to 150° C. and subsequent stirring at that temperature for 8 hours. This was followed by dilution of the mixture with ethyl acetate, filtration and distillative removal of the solvent in vacuo at 0.5 mbar and 70° C. to obtain 16 g (90% of theory) of 5-fluoro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carbaldehyde having a purity of 99% (melting point 68° C.).

1. filtrationThis was followed by dilution of the mixture with ethyl acetate, filtration and distillative removal of the solvent in vacuo at 0.5 mbar and 70° C.